Floats use LayoutUnits for all dimensions, it doesn't really make sense to be converting to ints for the placed floats tree.
Created attachment 216685 [details] Patch
Created attachment 216740 [details] New Patch
Comment on attachment 216740 [details] New Patch Looks good, r=me.
Comment on attachment 216740 [details] New Patch Note that there is a small but non-zero chance that this could cause small precision issues with tests when subpixel layout is enabled. I have run all of the tests locally, and have not seen any issues, so I don't expect there to be any new issues from this change.
Comment on attachment 216740 [details] New Patch Clearing flags on attachment: 216740 Committed r159166: <http://trac.webkit.org/changeset/159166>
All reviewed patches have been landed. Closing bug.